Question

in a mixture of milk and water, there is only 26% water. after replacing the mixture with 7 litres of pure milk, the percentage of milk in the mixture become 76%. the quantity of mixture is :

Answer 1

By calculating the initial and final concentrations of milk in the mixture and setting up an equation that balances the amount of milk before and after adding 7 liters of pure milk, we can determine the original and total volume of the mixture.

Step-by-step explanation:

In this mathematics question, a student is seeking to understand how the addition of 7 liters of pure milk affects the percentage of milk in a mixture that initially contains 26% water. We're given that after adding the 7 liters of milk, the mixture contains 76% milk.


To solve this problem, we'll use the concept of concentration and dilution of mixtures. The initial volume of the mixture can be determined by setting up an equation based on the percentage of water decreasing as a result of adding more milk.

We can let the original amount of the mixture be x liters, which contains 26% water and thus 74% milk. When we add 7 liters of milk, the total volume becomes x + 7 liters. Now, the mixture is said to contain 76% milk. By setting up an equation that equates the amount of milk before and after the addition, we can solve for x.

Initial amount of milk: 0.74x
Amount of milk added: 7 L

Total amount of milk after addition: 0.76(x + 7)

We can set up our equation as:

0.74x + 7 = 0.76(x + 7)

Solving for x gives us the original volume of the mixture before the addition of the 7 liters of pure milk, which we can then use to find the total amount of mixture.